Boiler furnace



U Jly,1-,rl930. E. L UNDGRN BOILERAFURNAGE Filed June 3, 1926 flxlllllllllllllllmmw ArroRNEyt Patented July 1, 193i) UNITED STATES PATENT EDWIN `Ii'lINDGrItEN, 0F FREDERICK, MARYLAND, ASSIGNOR TO INTERNATIONAL COM- BUSTION ENGINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE vBOILER FURNACE Application led June 3, 1926. Serial No. 113,378.

This invention relatesto boilers arranged in the shape ofa furnace, and has to do with combustion therein, and is especially useful where the fuel is to be burned in space, as, for example, where the fuel is in the form of powdered coal. n

One of the primary objects of the invention has to do withimprovements as to the admission of air for combustion.

Another object of the invention has to do with the obviating of certain operatino` difficulties incidentJ to the use of powdered coal, or carburetted oil, especially where such fuels are low grade, for example the practice of my invention tends to minimize the formation of deposits on the generating surfaces which would have the effect of impairing heat transmission. Again, in an installation fired in the manner hereinafter described, any unconsumed combustibles which may be brought into proximity with'the generating surfaces by centrifugal action are supplied with oxygen for their consumption. Blistering of the tubes which might occur when forcing the boiler to very high rates of firing is also prevented.

The foregoing, together with such other objects and advantages as may hereafter appear, or are incident to my invention, are obtained by moans of a construction which I have illustrated in the preferred form in r the accompanying drawings, wherein- Fig. 1 is a fragmentary vertical section through an installation embodying my improvements.

Fig. 2 is a fragmentary section taken on the line 2 2 of Fig. 1, and

F ig. 3 is a fragmentary section taken on the line 3--3 of Fig. 1. r

Referring now to Fig. 1, the reference character A indicates the boiler as a whole, such `boiler being arranged in the form of a furnace or combustion chamber. The boiler comprises the upper drums 7 and 8 and the lower' drums 9 and 10; the row of upright tubes 11 connecting the drums 8 and the row of upright tubes 12 connecting the drums 7 and 9; the side rows of tubes 13 defining the sides of the combustion space, such tubes being connected into the headers 14 at their upper ends, andthe headersr 15 at their lower ends, ythe headers 14, in turn, being connected to the drum 7 and the headers 15 to the drum 10; the row of roof tubes 16 connecting the drums 7 anl 8; and the bank ofv tubes 17 connecting the drums 9 and 10. A suitable sheathing 18 encloses the boiler at the front and rear, the sides and top, the combustion space ing open at the bottom, so that the gaseous products of combustion and the refuse pass downwardly into the settling chamber 19, and thence upwardly through the passage 2O to any suitable offtalre not shown. The fuel-in this instance, powdered coal-is admitted in the upper' regions of the combustion space at the four corners of the boiler by means of the burners 21. Onlya portion of the air for combustion is admitted with the coa-l, the balance of the air required for combustion being supplied through the casing 22-extending around the upper portion of the boiler, to which casing preheated air is supplied through the conduit 23 leading from any suitable form of preheater means (not shown) suitably located so as to be heated by the waste products, of combustion.

Preheated airV from the casingV 22 is ad mitted to the combustion space in the folf lowing manner. The tubes 11, 12 and13, have longitudinally extending lins 24 ex tending roughly about half the length of the tubes. These fins 24 are arranged on opposite sides of each tube and offset with respect to one another, so as to provide air spaces or air slits 25 between adjacent fins, as clearly shown in Fig. 2. By virtue of the provision of these slits air enters the combustion space from the casing 22 in a manner to sweep over the tubes'andins iii thin sheets of relatively high velocity.V In this connection, it is to be understood that any suitable blower mechanism is utilized to supply the casing 22 with preheated air. In this instance I have illustrated a blower 23EL for this purpose to which'preheatedl air is led,fas by means of a conduit 23h.

By supplying ythe air for combustion in this manner the surfaces of the tubes and c holler will produce a relatively enormous ing povided with longitudinally extendingi t im

quantity of steam.

Below the fins 24 the tubes 11, 1.2 and 13 are provided with longitudinally extending fins 26 which are arranged so as to substantially abut or align. The tubes 16 are also provided with fins 27 similar to the fins 26p.`

Thus, for all practical purposes, the combastion space is defined almost wholly by metallic heat transmitting surfaces.

AS Shown, the air is admitted for a distance both above and below and opposite the points of fuel admission, and. the length of the air passages will, in all cases, be determined in relation to the particular fuel to be burned, `always keeping in mind the desirability Offensuring that all particles of fuel am supplied with the requisite oxygen for their combustion. The control of the air susply is had by any suitable means, such as a am 1 28. Control of the air supplied aroun the burner nozzles is had by moving the dampers 29 toward or from the discharge end of the nozzles.

1. In combination, boiler tubes defining combustion space, and means for supplying fuel t0 the wmbustion space, said tubes being provided with longitudinally extending fims on o positesides, one offset with respect t0 the ot er and the tubes so spaced that the tins Vof adjacent tubes overlap one another with a' space therebetween.

2. In combination, boiler tubes defining combustion space, and means for lsupplying fuel ftothe combustion space, said tubes beon opposite sides, one offset with reb y to `the other and the tubes so spaced t the, ns of adjacent tubes overlap one i another with a space therebetween, together withmeans for supplying air to the spaces thus provided.

`3. In `combination,boiler tubes defining onmbnstionispaoe, means for supplying fuel t0' `the `immbustion space, said tubes being with longitudinally extending fins on qpasite sides, one offset with respect tov the `ot er and the tubes so spaced that the ns of ,adjacent tubes overlap one another `with a space therebetwen, together rwith an air cha mber surrounding the boiler and means for supplying the same with air.

4. In combination, a furnace shaped tubular boiler, means for admitting Jfuel to bc burned in suspension in one region of the boiler, longitudinal fins on the 'tubes near the point of fuel admission arranged on each of two opposite sides of the tubes in offset relation to one another so that the fins of adjacent tubes overlap one another with a space therebetween, and longitudinal fins on the tubes cooperating with the vtubes to form substantially continuous walls in a portion removed from said region.

In testimony whereof I have hereunto signed my name. 4

EDlVIN LUNDGREN. 

